Electronic lock apparatus

ABSTRACT

An electronic lock apparatus includes a tumbler key mechanism having tumblers as part of a series of switches for setting a first coded electronic signal in response to the insertion of a key. A second code means connected to the switches generates a second coded electronic signal in response only to receipt of a proper first electronic coded signal, and an electronic means responsive to said second coded electronic signal decodes said second electronic signal and generates an initiating signal to initiate the operation of a lock. The entire electronic lock apparatus is disabled if said series of switches for setting the first coded electronic signal are not set within a predetermined time frame.

D United States Patent 1 [111 3,764,859

Wood et al. Oct. 9, 1973 ELECTRONIC LOCK APPARATUS [75] Inventors:Charles W. Wood; Edwin S. Wydro, j f g f g g l J 0th of hi3, Pa 8816 anxammer arry 0086, I. b p Attorney-Arthur H. Seidel et a1. [73] Assignee:Wilmer Gross, Jack Seidman and Jules I. Whitman, all of Phila- [57]ABSTRACT delphla, An electronic lock apparatus includes a tumbler key[22] Filed: May 30 1972 mechanism having tumblers as part of a series ofswitches for setting a first coded electronic signal in PP response tothe insertion of a key. A second code means connected to the switchesgenerates a second [52] Us. Cl 317/134 70/278 70/370 coded electronicsignal in response only to receipt ofa 51 260/44 367/10 proper firstelectronic coded signal, and an electronic [51] Int CL E05b 49/00 meansresponsive to said second coded electronic sig- [581 Field I 97 200/42nal decodes said second electronic signal and gener- 307/10 ates aninitiating signal to initiate the operation of a lock. The entireelectronic lock apparatus is disabled [56] References Cited if saidseries of switches for setting the first coded electronic signal are notset within a predetermined UNITED STATES PATENTS time frame 3,639,9062/1972 Tritsch 317/134 2,905,926 9/1959 Aid 317 134 x 12 Clams, 6Drawlng Flgures 3,641,396 2/1972 Kossen 317/134 n 3,610,943 l0/l971Jones 3l7/l34 r0 Lac/r Hyji- PATENTEU [1m 9 SHEET 1 BF 5 FIG.

PATENTEU GET 9 I975 SHEET 2 0F 5 PATENTEB 91973 SHEET 5 0F 5 ML QVS QkELECTRONIC LOCK APPARATUS This invention relates to an electronic lockapparatus. More particularly, this invention relates to an electroniclock apparatus that operates only upon the generation of properelectronic codes.

Heretofore various coded electronic locks have been proposed. Such locksemploy a coded electronic signal generated upon the insertion of a keyinto a key mechanism. The coded signal thus generated is used toinitiate a mechanism for driving the lock bolt. The coded signal may bean analog or even binary. Examples of such locks are shown in U.S. Pat.Nos. 3,392,558, 3,411,046, 3,408,838, 3,415,087 and 3,392,559. Furtherpatent references reflecting such technology can be found in the U.S.Patent Office classified in Class 340, Communications, Electrical;subclass 63, Theft or Burglar; subclass 64, Ignition Circuit Controled;and subclass 147, Selective.

The present invention improves upon such technology by providing anelectronic lock apparatus that cannot be picked either by mechanical orelectrical means. In accordance with the present invention the lockmechanism incorporates the concept of coded electronic signals. However,the present invention uses at least two coded electronic signals. Thefirst coded electronic signal is set by the insertion of a key into atumbler mechanism. The second coded electronic signal is set only uponthe generation of a proper first coded electronic signal. The lock boltmechanism can be operated only upon the generation of a proper secondcoded electronic signal. The second electronic coded signal hassufficient permutations that it cannot be readily decoded except byextensive effort.

Since the present lock mechanism depends upon the setting of the firstelectronic code, the invention also provides means to prevent thesetting of such code except by the insertion of the proper key.Mechanical picking of the lock is prevented by providing a timer thatdisables the entire lock mechanism if the first coded signal is not setwithin a predetermined time frame. Still further, means are provided forpreventing persons from manufacturing a key by first feeling the properkey settings and then making the key on machinery available for thatpurpose. This is accomplished by splitting the tumblers into two or moresections such that the cylinder of the lock may rotate at any one of alarge number of tumbler positions. However, only one of such positionswill set the first coded electronic signal.

The present invention has particular use as an antitheft mechanism forautomotive vehicles. However, it should be understood that theelectronic lock apparatus is in no way intended to be limited to useonly with such vehicles.

At the present time the typical automobile and other vehiclesincorporate a combined lock and starting switch mounted on the steeringcolumn. In its off position and with the key removed, the lock mechanismdisables the electrical system for the automobiles engine and alsoimmobilizes the steering mechanism. Unfortunately, such lockingmechanisms can be readily removed by force and the electrical systemswitched on by a technique known as jumping.

In accordance with the present invention a vehicle is disabled not onlyby the means described above, but also by mechanically disabling orlocking a part of the vehicle that is not readily accessible to thethief attempting to steal an automobile in a street, parking lot orother place accessible to the public. By way of example, an automobilecan be disabled by cutting off the flow of oil through the transmission.The apparatus for enabling the flow of oil through the transmission canbe located therein and hence would be accessible only by entry into thetransmission using a great amount of effort. Of course, there are manyother ways to disable an automobile as pointed out hereinafter.

In accordance with the present invention, the lock apparatus describedabove is used to operate this inaccessible enabling-disabling mechanism.Since such mechanism is not readily accessible and since the lockmechanism cannot be picked, the stealing or unauthorized removal ofautomobiles by any means except physically towing the vehicle isprevented. Since most vehicles are stolen by forceably removing the lockmechanism and jumping the ignition system as described above, all withina period of five minutes, the present invention should greatly reducethe number of vehicles stolen each year.

For the purpose of illustrating the invention, there are shown in thedrawings forms which are presently preferred; it being understood,however, that this invention is not limited to the precise arrangementsand instrumentalities shown.

FIG. 1 is a partial sectional view of the electronic lock apparatus inaccordance with the present invention.

FIG. 2 is a partial transverse sectional view taken along the line 22 inFIG. 1.

FIG. 3 is a partial sectional view taken along the line 3-3 in FIG. 1.

FIG. 4A is a portion of the electronic circuitry used in the presentinvention, shown schematically.

FIG. 4B is the remaining portion of the electronic circuitry.

FIG. 5 is a partial transverse sectional view of another embodiment ofthe present invention.

Referring now to the drawings in detail, wherein like numerals indicatelike elements, there is shown in FIGS. 1 and 2 a partial view of amodified cylinder lock designated generally as 10.

As shown, the cylinder lock 10 includes a rotatably mounted plug orcylinder 12 in which is formed the keyway 14. A key 16 is shownpositioned in the keyway 14.

In the locked position, a number of pin tumbler sets 18, 20, 22, 24 and26 of different overall length are pressed down by springs 28, 30, 32,34 and 36 to engage with holes in the cylinder 12, thereby preventingthe latter from rotating. When the key is inserted into the lock asillustrated in FIG. 1, the lower segments of the pin tumbler sets areraised by exactly the correct amount to bring their tops flush with theouter surface of the cylinder. As the segments of each tumbler areseparate, i.e., not connected, the cylinder is then free to rotate whenthe key is turned. The cylinder actuates a bolt or the like to unlockthe mechanism.

The cylinder lock 10 described herein may be associated with thesteering column of an automobile. As such, it unlocks the steeringcolumn and permits the wheels to be turned from inside the automobile.In addition, the continued rotation of the cylinder 12 engages switcheswhich permit the vehicle to be started by energizing th ignition. All ofthe foregoing is conventional and therefore need not be described indetail.

Rather, only modifications to such a cylinder lock for an automotivevehicle are described herein.

Although an automotive vehicle lock is described, it should beunderstood that the invention is no wise in tended to be so limited. Thelock could, for example, be used in a door. The door referred to hereincould be a closure for any building, apartment, safe, cabinet, box orany other place where locks are used to prevent the opening of astructure. Still further, the lock could be used in any mechanicalmechanism in accordance with the principles described herein withrespect to disabling an automotive vehicle.

Referring now to FIG. I, it should be noted that each of the pin tumblersets 18-26 is divided into four segments so as to provide threeinterfaces. Reading from bottom to top, the first three segments aredelineated by the letters a, b, and c. By way of example, pin tumblerset 20 includes segments 20a, 20b, and 20c. The fourth segment of eachset 18-20 is elongated and designated 48, 50, 52, 54 and 56. The purposefor dividing each of the sets of pin tumblers 18-26 into segments is toprevent determination of the initial (first) code by measuring theposition of each tumbler that would permit the cylinder 12 to turn andthen using such measured positions to manufacture a key on machinesavailable for that purpose. This would be possible if conventionaltwo-piece tumblers having only one interface were used.

The illustrated embodiment shows five sets of pin tumblers. It should beapparent to those skilled in the art that locks with more or less setsof pin tumblers can be used. A six pin tumbler lock is conventionallyavailable as is a four pin tumbler lock. An even larger or smallernumber of pin tumblers can be used as desired.

It is immediately apparent that by dividing each of the pin tumblersinto three or more segments the lock is much easier to mechanicallypick. Stated otherwise, the increased number of interfaces raise thecombination of pin tumbler positions where the cylinder 12 will turn fora specific key. In particular, three interfaces for five sets of pintumblers raise the combination where the lock will turn for a specifickey or tumbler arrangement from 5 to 243. For a conventional 5 tumblerlock, there are 12,000 tumbler or key arrangements as is known.

Such an increase in the ease by which the lock may be mechanicallypicked is used as a trade off to substantially, completely prevent thedetermination of the electrical code. As stated above, it preventspicking the lock to get an initial code which is determined by the pintumbler position using only the correct key.

In accordance with the present invention, an unauthorized attempt tomechanically pick the lock will result in the cylinder 12 being morereadily rotated. In the case of an automobile, this will permit thesteering column to be unlatched and also, presumably but notnecessarily, permit the automobile engine to be started. This is allowedto occur because the unauthorized starting (jumping) of an automotiveengine remains reasonably easy to accomplish regardless of theprotective devices that have been incorporated heretofore. However,starting the automotive engine does not necessarily mean that thevehicle can be operated. In accordance with the present invention, theonly way that the automobile can be operated is to have the properinitial code which in turn unlatches a vehicle disabling mechanismlocated at a part of the vehicle that is not readily accessible to aperson making unauthorized use of the vehicle.

There are several methods for disabling an automobile. One could disablethe oil flow to the hydraulic lifters which would prevent the valvesfrom opening. Another approach is to pin the flywheel. This can preventengine rotation, but is disadvantageous because it could cause seriousdamage to both the engine and transmission should the vehicle be pushed,towed, or hit. Another method for disabling the vehicle is to lock ordisconnect the gear box at the lower end of the steering column. Thedisadvantage here is that a failure in this device will cause a serioussafety hazard. A positively secured wheel lock also presents serioussafety hazards in case of a lock-up at highway speeds. Also, police orother emergency vehicles could not remove the vehicle.

Still another method of disabling the vehicle is to shut off the fuelflow to the carburetor. Thus, the vehicle could be moved only as far asthe fuel in the carburetor reservoir permits. Unfortunately, thisapproach is readily beaten by an unauthorized user who could tap asupplemental fuel supply into the fuel line at the carburetor. Stillanother approach would be to prevent fuel flow from the carburetor jets.This could be accomplished but would require complete redesign of thecarburetors in use on vehicles today.

Other approaches are to provide control of a vent port in the intakemanifold system or control of a butterfly valve mounted between thecarburetor and the engine. All of these require redesign and retoolingalthough less so with respect to the butterfly valve approach.

One approach which appears to accomplish the purposes of the inventionis to bypass the automatic transmission oil using a solenoid controlledvalve. Thus, unless the solenoid valve is properly actuated by thereceipt and decoding of a proper code, oil does not flow in the correctmanner through the transmission to permit the vehicle to be moved underits own power. The advantage of this is that it requires little or noretooling, except perhaps for the outer housings of the transmission.Also, the environment inside of a transmission is relatively cool (nomore than about 200F) and therefore is not particularly hostile to asolenoid valve and electrical decoding circuits used with the presentinvention. Still further, the interior of a transmission is notaccessible except by extensive effort and a properly equipped shop.

The foregoing points up the principles of the present invention. Thus,no attempt is made to inhibit the mechanical picking of a lock. Rather,the ability to pick it is enhanced. The tumblers themselves are part ofelectronic switches which define a particular code. The first code isdifficult to ascertain because of the several hundred positions at whichthe lock can be mechanically picked while only one of those positionsdefines the proper code position. This first code is used to initiate asecond electronic code which in turn is transmitted to a decoder locatedin an inaccessible part of the mechanism or device being protected; e.g.the transmission of a vehicle. The second electronic code is decoded andthe remote portion operated only when the proper or second code isreceived. To prevent someone from ultimately picking the lock by tryingall of the possible enhanced combinations, the electronic lock isprovided with a device to completely disable it unless it is pickedwithin a very short time frame.

As previously indicated, the pin tumbler sets 18-26 are used to generatean initial code. This initial code is represented by whether a series ofswitches complete an electrical circuit or not when a proper key isinserted into the cylinder. These switches designated 118, I20, 122, 124and 126 are shown schematically in FIG. 4A. They correspond directly tothe pin tumbler sets 18, 20, 22, 24 and 26. Thus, by way of example, pintumbler set 18 is illustrated as switch 118 in FIG. 4A, and so forth.

Still further, each switch is designated in FIG. 4A by the letters N.O.or NC. The designation N.O. is used to indicate that a switch does notcomplete a circuit when the proper key is inserted into the cylinder 12while the designation NC. is used to indicate that a switch doescomplete a circuit. In the circuit illustrated in FIG. 4A, the circuitis completed to ground.

The choice of whether a particular switch (pin tumbler set) completes ordoes not complete a circuit for a particular key is predetermined by thelock manufacturer, but such determination is wholly arbitrary. Moreover,it is varied from key to key. As such, the combination of switches118-l26 (pin tumbler sets 18-26) represents the initiating means forgenerating a first coded electronic signal.

Referring once more to FIGS. 1 and 2, there is shown a lock constructionwhereby the segments of the pin tumblers can be used to complete or notcomplete an electrical circuit.

As best shown in FIG. 1, eact set of pin tumbler slide in alignedopenings formed in the cylinder 12 and lock housing 38 when the cylinderlock is in its locked position. As best illustrated in FIG. 2, theopening in which the sets of pin tumblers slide within the lock housing38 is formed by an insulator 40. The pin tumbler opening 39 is linedwith a conductive sleeve 42 that extends to a point adjacent to butspaced away from the interface between lock housing 38 and cylinder 12.The spacing is provided by a collar 44 made of an insulating material.

Conductor 46 connects the sleeve 42 to the electronic circuit, and thecylinder 12 is electrically connected to ground. Therefore, a circuitcan be completed to ground through the pin tumblers depending uponwhether a particular segment or segments of pin tumblers bridging thespace between sleeve 42 and cylinder 12 as defined by collar 44 areconductive or not conductive. Since the switch 118 is not connected toground when the key 16 is inserted into the lock, the segment 18c and18b are made of non-conductive material. However, the switch 122 is tobe connected to ground when the proper key 16 is positioned in the lock.This is accomplished by providing the segment 22c and 22b with at leastan outer conductive coating to complete the circuit across the collar 44associated with the pin tumbler set 22.

It should be apparent from the foregoing, that the segments of the pintumblers may be made of an insulating material, such as plastic. Thosepin tumbler segments that are to complete the circuit and thus define anN.C. switch, may be made of copper or brass or may be plastic coatedwith a thin layer of conductive material. Moreover, other combinationsof conductive and non-conductive materials may be used to accomplish thesame purpose.

It should also be understood that the present invention is not limitedto the use of conductive sleeves as illustrated in FIGS. 1 and 2. Othermeans may be used to provide electronic switches operatively associatedwith the sliding pin tumbler sets 1826.

As shown in FIG. 5, the housing 38' supports by way of example, a pintumbler set 18' made of plastic or brass, as desired. The pin tumblerset 18 is topped by an elongated segment 48' whose function in relationto the embodiment illustrated in FIGS. 1 and 2 is described in moredetail hereinafter. An opening 58' is formed near the top of theelongated sgement 48' and defines a means for passing electromagneticradiation from an emitter 60' to a photodetector 62'. The emitter 60 is,by way of example, a light emitting diode which emits infraredradiation. The photodetector 62' is a transistor device sensitive toinfrared radiation.

The operation of the embodiment illustrated in FIG. 5 to provide theelectronic switch should be apparent from what has been described. Thus,the photodetector 62 will receive or not receive radiation dependingupon the presence or absence of an opening 58' in the elongated segment48'. By repeating the elements illustrated in FIG. 5 for each tumblerset, an electronic switch, based upon the detection of electromagneticradiation, has been provided.

The advantage of the optical approach used in the embodiment of FIG. 5is that all of the segments of the pin tumbler sets can be made of thesame material and hence slide with the same amount of friction. Hence,there will be no feel to the lock that could tell an expert which of thesegments is insulative and which is conductive.

The pins can take other forms for providing switches. Mechanical switchcontacts can be used. Another example would be to use magnetic detectorssuch as magnetic diodes, Hall devices, or small reed switches.

Referring now to FIG. 4A, the manner of processing the code initiated bythe switches 1 18-126 is described. As shown, each of the switches118-126 is connected to one of six inputs to a NAND gate 64. The wellknown function of a NAND gate is that it will provide a logical O at itsoutput when all of its inputs have a logical I applied thereto. Bycompleting a circuit to ground, each of the switches 120, 122 and 126provides the requisite logical I at the input of NAND gate 64. Switch118 is connected to inverter 66 which inverts the logical 0 generated bythat switch and converts it to a logical I Inverter 68 performs the samefunction for N.O. switch 124.

Inverters 66 and 68 are remotely located away from the switches 118-126and preferably encapsulated together with NAND gate 64 so that physicalinspection of the switches would not reveal which defines an N.C. orN.O. switch. Indeed, it is proposed that the inverters 66 and 68together with the NAND gate 64 be made in a single integrated circuitchip so that even if access to the chip could be had, it would beimpossible to tell which were the N.O. switches and which were the NC.switches.

As previously indicated, the switches 118-126 provide five of the sizinputs to the NAND gate 64. The sixth input is provided by a timerdescribed hereinafter. The timers function is to provide a logical I atthe NAND gate 64 only for a limited period (hereinafter sometimesdescribed as a time frame). If the NAND gate 64 does not have alllogical Is within a predetermined time frame, then the timer maintains alogical at its input and only a logical l appears at the output of theNAND gate 64. This disables the lock apparatus as hereinafter described.

The output of NAND gate 64 is connected to the input of NAND gate 70which functions as an inverter to invert the output of NAND gate 64 froma logical O to a logical l or vice versa.

It should be understood that it is not intended to limit this inventionto the use of NAND gates as herein described. NAND gates are readilyavailable and therefore have been chosen to illustrate the invention.However, AND gates could be used with equal facility. This appliesthroughout the entire description of the invention.

The output of the NAND gate 70 is connected to a bus as 72 which in turnis connected to all of the encode gates designated generally as 74. Thepresence of a logical l at one of the terminals of the encode gates 74enables all of the gates and results in the generation of a second codedelectronic signal.

The encode gates 74 are also NAND gates in the illustrated embodiment.However, they could be diode gates or any other gate that provides therequisite logic output.

Each of the other terminals of the encode gates is provided with eithera ground or an open circuit selected completely at random and in anon-repeating fashion. Whether a particular gate is connected to groundor to an open circuit is determined by the lock manufacturer and this inturn determines the second coded electronic signal. The number ofpermutations of the code for any set of encode gates is mathematicallydetermined by the number of gates. The number of permutations forparticular codes is equal to 2 where n represents the number of gates.Thus, for either gates there are 256 permutations. For sixteen gatesthere would be 65,536 permutations.

The number of encode gates illustrated is eight. However, the number ofsuch gates may be made larger or smaller. increasing the number of gatesincreases the amount of security.

The encode gates 74 are preferably encapsulated with the NAND gates 64and 70 as well as the inverters 66 and 68. Indeed, they may bemanufactured as part of one integrated circuit chip with such NAND gatesand inverters. The chip is preferably encapsulated in a plasticmaterial, such as epoxy. It may be physically located adjacent tocylinder lock 10.

The purpose of the encode gates is to prevent someone from tapping wiresto look back into the electronic system to determine the first code.Anyone who taps into the wires leading from the output of the encodegates 74 get no electronic information that would permit the lock to bepicked. Everything looks electronically alike.

The conductors connected to the outputs of the encode gates 74 areconnected to a decoder located at some remote, inaccessible position ina vehicle or other device or structure being protected by the lockapparatus. If desired, dummy wires could be incorporated in randomamounts to prevent even knowing the number of code permutations bycounting the wires.

The timer, already mentioned, is also illustrated in FIG. 4A. The timerconsists of five series connected switches 180, 182, 184, 186 and 188.Each of these switches is operatively associated with the pin tumblersets 18, 20, 22, 24 and 26 as hereinafter described. The switches180-188 connect the input of NAND gate to ground. Should any one ofthese switches be opened, the input of NAND gate 90 goes from a logical0 to a logical 1. Therefore, the output goes from a logical l to alogical 0. Stated otherwise, the output of NAND gate 90 is normally alogical l, but it reverses and goes to a logical 0 should any one of theswitches 180-188 be opened.

The switches 180-188 are associated with pin tumbler sets 18-26.Accordingly, should any one of the pin tumblers 26 be disturbed, such asis necessary to mechanically pick the lock, then one of the switches180-188 will be opened.

The output of NAND gate 90 is connected to an inverter 92 in the form ofanother NAND gate. NAND gate 92 therefore functions to invert a logical0 to a logical l when any one of the switches 180-188 is opened. Assuch, NAND gate 92 acts as a switch in that it allows the capacitor 94to commence charging up to the applied voltage which, in this case is 5volts applied through resistor 96. Resistor 98 couples the output ofNAND gate 92 to capacitor 94. Resistor 100 couples capacitor 94 to theinput of OR gate 102. Therefore, the presence of'a logical 0 at theoutput of NAND gate 92 when all of the switches -188 are closed, clampsthe capacitor 94 to ground.

Resistor 104 feeds back the output of OR gate 102 to its input. As thusconnected, OR gate 102 functions as a level sensor. In particular, it isa Schmitt trigger circuit. The level at which it is set is substantiallybelow the illustrative 5 volts applied to capacitor 94. it could, forexample, be set to generate a pulsed output signal at 2 volts.Therefore, when the voltage on capacitor 94 goes above the presetvoltage, both the input and output of OR gate 102 goes from a logical Oto a logical l. The amount of time for this to occur depends upon the RCtime constant as determined by the values of resistor 96 and capacitor94. Preferably, it is set at between 1 to 5 seconds.

Recalling the description of the timer aforesaid, it should be apparentthat the switches 118-126 must present the correct first code to theinput of NAND gate 64 within the preselected time frame. The output ofNAND gate 106 is connected to the sixth input of NAND gate 64. It is aprecondition to the operation of the lock apparatus that all logical lsappear at the input of NAND gate 64. Hence, the appearance of a logical0 at the termination of the time frame disables the entire electroniccircuit. If this does not occur, then -a logical I will appear at theoutput of NAND gate 90 and hence also at the input of NAND gate 106.This means the NAND gate 106 will have a logical 0 at its output.

The advantage of the foregoing is that even if an intruder shouldstumble upon the correct first code, it would take more time bymechanical picking than is allowed by the time frame. Once the timeframe is exceeded, the timer maintains a logical 0 at one of the inputsof NAND gate 64 and hence disables the lock apparatus.

The timer is reset at any time by withdrawing the key or any othermechanism that is disturbing the pins. This allows the pins to againconnect the input of NAND gate 90 to ground and hence reset the timer byclamping capacitor 94 to ground. This procedure permits an authorizeduser to the lock who happens to fumble with the key to withdraw the keyand re-insert it within the time frame. When the proper key is insertedwithin the time frame, then all logical ls will apear at the input ofNAND gate 64 and a logical 1 will be applied to the bus 72. The timeframe is chosen to be long enough to permit the proper key to beinserted into the cylinder 12, but to prevent mechanical picking of thelock. As previously indicated, a preferred time frame would be between 1and 5 seconds.

If the proper key is inserted into cylinder 12 within the time frame, alogical 0 is connected by conductor 108 from the output of NAND gate 64to the other input of NAND gate 106. This logic 0 provides a logical lat the output of NAND gate 106 and hence locks out the timer regardlessof the logical condition of the output of OR gate 102.

As previously indicated, the operation of the timer depends upon thephysical disturbance of the position of the pin tumbler sets 18-26.FIGS. 1, 2 and 3 illustrate how this is accomplished.

As illustrated in FIG. 1, the upper portion of each pin timbler set 18,20, 22, 24 and 26 includes an elongated segment 48, 50, 52, 54 and 56,respectively. Each elongated segment includes a bar designatedrespectively as 128, 130, 132, 134 and 136 which projects upwardlythrough an opening in a printed circuit 138 as illustrated in FIG. 3.

The top of each bar 128-136 is provided with a projecting flange 140,142, 144, 146 and 148 respectively. At least the bottom of each flangeis made of an electrically conductive material such as copper. When thekey 16 is withdrawn from the keyway 14, each of the flanges 140-148rests on the top surface of the printed circuit 138. The printed circuit138 is divided into conductive segments 150, 152, 154, 156, 158 and 160.Accordingly, the conductive flanges complete a circuit to ground throughthe segments 150-160 when the key 16 is withdrawn. However, should anyone of the pin tumbler sets 18-26 be raised either by the insertion ofakey or by a mechanical pick, so will one of the flanges 140-148.Accordingly, the circuit through the printed circuit board 138 will bebroken and the timer will commence functioning as described above.

The foregoing describes one means for providing the requisite switchesfor operating the timer. It should be understood, however, that othermeans for accomplishing the same purpose may be provided. The describedembodiment illustrates but one method by which the disturbance of anyone of the pin tumbler sets initiates the operation of the timer. Othermeans for accomplishing the same purposes will be apparent to thoseskilled in the art.

As previously stated, the insertion of a proper key into the lockresults in the presentation by NAND gate 70 of a logical l on bus 72.This in turn results in the generation of a second coded electronicsignal on the output lines of the NAND gates of encode gates 74. Thissignal coded electronic signal is conducted to the decoder schownschematically in FIG. 4B. The decoder is located within an inaccessiblepart of the device being protected, such as the transmission of anautomobile. It too is preferably an encapsulated integrated circuit chipincorporating the electronic elements schematically illustrated in FIG.4B.

As shown, all of the conductors from encode gates 74 which define alogical l are connected to the bus 200 which is connected to the inputsof NAND gate 202.

All of the conductors which carry a logical 0 are connected to inverters204, 206 and 208, for example which invert the logical 0 to a logical 1.Thus, all logical ls appear on the buss 200. The presence of all logicalls on the bus 200 result in a logical 0 at the output of NAND gate 202.This is inverted to a logical l by the NAND gate 210. NAND gate 212inverts the signal back to a logical 0 thereby causing NAND gate 214 tohave a logical l at its output. This logical l is conducted to the baseof transistor 216 which functions as a switch. Transistor 216 controlssolenoid 218. Thus, the presence of a logical 1 at the base oftransistor 216 permits solenoid 218 to be energized. The operation ofsolenoid 218 controls a mechanism which enables the device beingprotected. For example, it could control a valve that permits oil toproperly flow through the transmission and permit the vehicle to beoperated. It could also operate the bolt of a lock in other devices.Thus, the lock apparatus has completed its basic function. Of course,the solenoid 218 is but one form of device that can be used to lock orunlock the device being protected.

NAND gate 212 functions as an enable detector. It may be omitted fromthe circuit if an enabling function is not required. The conductor 220connects one of the inputs of NAND gate 212 back to the lock. It is runas an extra line together with the conductors carrying the secondencoded signal. At the lock electronic means are provided to place alogical 1 on conductor 220 and hence at the input of NAND gate 212 onlywhen the vehicle ignition system is on. This provides added security byrequiring yet another act before the solenoid 218 can be energized.Stated otherwise, solenoid 218 cannot be operated unless a logical 1appears on line 220. In the case of an automotive vehicle, this could bethe switching on of the ignition system. This is just one more act whichmust be accomplished if the lock system is to be picked.

There are several advantages to the foregoing invention which should bepointed out with more particularity, particularly as applied topreventing automotive theft. The foregoing invention effectivelyprevents the unauthorized use or theft of an automobile from a street,parking lot, driveway or other open area where a vehicle has beenparked. In accomplishing this, operator (driver) requirements remainunchanged. Thus, the starting and driving procedures for the vehicle areunmodified.

Yet another advantage of the present invention is that its cost ofimplementation is comparatively low, not more than a few dollars.Moreover, it has the advantage of simplicity and reliability, nor doesit jeopardize the safety of the occupant. Still further, it does notaffect the performance of the engine or any antipollution devicesassociated therewith.

The use of the coded electronic signal in the manner described preventsthe effective use of standard jumping techniques. Mechanically pickingthe lock is circumvented by the timing circuit that requires all codedsignals to be present within the present time frame. Forceableextraction of the lock from the steering column results in an impropercode and hence prevents current techniques for stealing an automobile.Without a key, entry into the driving compartment of the vehicle is ofno value to the unauthorized user. Hence, a truly effective anti-theftdevice is provided.

It should also be pointed out that the electronic lock apparatusdescribed herein does not require the use of a rotatable key cylinder.That much of the lock is conventional and is incorporated to preserveknown habits. It should be apparent that the insertion ofa key and displacement of the tumblers is sufficient to operate the lock. Thus, thelock could be incorporated into a system which does not use a rotatablekey cylinder. For example, the insertion of the key could be used toswitch on a hidden motor to slide a bolt into or out of engagement witha jamb. Such a device may have utility in the home to better securedoors or windows.

The present invention may be embodied in other specific forms withoutdeparting from the spirit or essential attributes thereof and,accordingly, reference should be made to the appended claims, ratherthan to the foregoing specification as indicating the scope of theinvention.

We claim:

1. An electronic lock apparatus comprising:

a. key means;

b. first code means for generating a first coded electronic signal inresponse to operation of the key means;

c. second code means connected to the first code means for generating asecond independently determinable coded electronic signal in responseonly to the generation of the first electronic coded signal; and

d. electronic means responsive to said second coded signal to decodesaid second coded signal and generate an initiating signal forinitiating the operation of aa lock means.

2. An electronic lock apparatus, comprising:

a. key means including a tumbler mechanism;

b. said tumbler mechanism including tumblers and electronic switcheswhich are opened or closed in response to the position of the tumblers;

c. said electronic switches defining a first code means for generating afirst coded electronic signal in response to operation of the key means;

d. second code means connected to the first code means for generating asecond independently determinable coded electronic signal in responseonly to the generation of the first electronic coded signal; and

e. an electronic means responsive to said second coded signal to decodesaid second coded signal and generate an initiating signal forinitiating the operation of a lock means.

3. An electronic lock apparatus in accordance with claim 2 wherein saidtumblers are divided into three or more segments.

4. An electronic lock apparatus, comprising:

a. key means;

b. first code means for generating a first coded electronic signal inresponse to operation of the key means;

0. timer means for disabling the lock apparatus if a first proper codedelectronic signal is not generated within a predetermined time frame;

(1. second code means connected to the first code means for generating asecond independently determinable coded electronic signal in responseonly to the generation of a proper first electronic coded signal; and

e. electronic means responsive to said second coded electronic signal todecode said second coded signal and generate an initiating signal forintitiating the operation of a lock means.

5. An electronic lock apparatus, comprising:

a. key means including a tumbler mechanism having a plurality oftumblers therein;

each of said tumblers being divided into three or more segments forpermitting said tumbler mechanism to be operated in more than oneposition of said tumblers;

c. first code means for generating a first coded electronic signal inresponse to operation of the key means;

d. said first code means including electronic switches for setting thefirst coded electronic signal;

e. said electronic switches comprising said tumblers and conductive ornon-conductive segments thereof for completing or not completing anelectronic circuit depending on the position of said tumblers;

f. second code means connected to the first code means for generating asecond independently determinable coded electronic signal in responseonly to the generation of the first electronic coded signal; and

g. electronic means responsive to said second coded signal to decodesaid second coded signal and generate an initiating signal forinitiating the operation of a lock means.

6. An electronic lock apparatus, comprising:

a. key means including a tumbler mechanism having a plurality oftumblers therein;

b. at least one of said tumblers being divided into three or moresegments for permitting said tumbler mechanism to be operated in morethan one position of said tumblers;

c. first code means for generating a first coded electronic signal inresponse to operation of the key means;

d. said first code means including electronic switches for setting thefirst coded electronic signal;

e. said electronic switches including said tumblers for completing ornot completing an electronic circuit depending on the position of saidtumblers;

f. second code means connected to the first code means for generating asecond independently determinable coded electronic signal in responseonly to the generation of the first electronic coded signal; and

g. electronic means responsive to said second coded signal to decodesaid second signal and generate an initiating signal for initiating theoperation of a lock means.

7. An electronic lock apparatus, comprising:

a. key means including a tumbler mechanism having a plurality oftumblers therein;

b. at least one of said tumblers being divided into three or moresegments for permitting said tumbler mechanism to be operated in morethan one position of said tumblers;

d. timer means for disabling the lock apparatus if a proper first codedelectronic signal is not generated within a predetermined time frame;

c. said first code means including electronic switches for setting thefirst coded electronic signal;

f. said electronic switches including tumblers for completing or notcompleting an electronic circuit depending on the position of saidtumblers;

g. second code means connected to the first code means for generating asecond independently determinable coded electronic signal in responseonly to the generation of the first electronic coded signal; and

h. electronic means responsive to said second coded signal to decodesaid second signal and generate an initiating signal for initiating theoperation of a lock means.

8. An electronic lock apparatus, comprising:

a. key means including a tumbler mechanism having a plurality oftumblers therein;

b. at least one of said tumblers being divided into three or moresegments for permitting said tumber mechanism to be operated in morethan one position of said tumblers;

c. first code means for generating a first coded electronic signal inresponse to operation of the key means,

d. timer means for disabling the lock apparatus if the proper codedelectronic signal is not generated within a predetermined time frame;

e. second code means connected to the first code means for generating asecond independently determinable coded electronic signal in responseonly to the generation of the first electronic coded signal; and

. electronic means responsive to said second coded electronic signal todecode said second coded signal and generate an initiating signal forinitiating the operation of a lock means.

9. An electronic lock apparatus comprising:

a. key means including a non-rotatable key cylinder and at least onetumbler in said cylinder;

b. said tumbler being unitary and displaceable in response to theinsertion of a key into said cylinder;

c. first code means for generating a first coded electronic signal inresponse to displacement of said tumbler;

(1. second code means connected to the first code means for generating asecond independently determinable coded electronic signal in responseonly to the generation of a first electronic coded signal; and

e. electronic means responsive to said second coded signal to decodesaid second coded signal and generate an initiating signal forinitiating the operation of a lock means.

10. An electronic lock apparatus in accordance with claim 9 wherein saidfirst code means includes at least one electronic switch for setting thefirst coded electronic signal, said electronic switch being responsiveto the displacement of said tumbler by a key means.

11. An electronic lock apparatus in accordance with claim 9 includingtimer means for disabling the lock apparatus if a proper first codedelectronic signal is not generated within a predetermined time frame.

12. A electronic lock apparatus, comprising:

a. key means including a tumbular mechanism having a plurality oftumblers therein;

at least one of said tumblers being divided into three or more segmentsfor permitting said tumbler mechanism to be operated in more than oneposition of said tumblers;

c. first code means for generating a first coded electronic signal inresponse to operation of the key means;

d. second code means connected to the first code means for generating asecond independently determinable coded electronic signal in responseonly to the generation of the first electronic coded signal; and

e. electronic means responsive to said second coded electronic signal todecode said second coded signal and generate an initiating signal forinitiating the operation of a lock means.

1. An electronic lock apparatus comprising: a. key means; b. first codemeans for generating a first coded electronic signal in response tooperation of the key means; c. second code means connected to the firstcode means for generating a second independently determinable codedelectronic signal in response only to the generation of the firstelectronic coded signal; and d. electronic means responsive to saidsecond coded signal to decode said second coded signal and generate aninitiating signal for initiating the operation of a lock means.
 2. Anelectronic lock apparatus, comprising: a. key means including a tumblermechanism; b. said tumbler mechanism including tumblers and electronicswitches which are opened or closed in response to the position of thetumblers; c. said electronic switches defining a first code means forgenerating a first coded electronic signal in response to operation ofthe key means; d. second code means connected to the first code meansfor generating a second independently determinable coded electronicsignal in response only to the generation of the first electronic codedsignal; and e. an electronic means responsive to said second codedsignal to decode said second coded signal and generate an initiatingsignal for initiating the operation of a lock means.
 3. An electroniclock apparatus in accordance with claim 2 wherein said tumblers aredivided into three or more segments.
 4. An electronic lock apparatus,comprising: a. key means; b. first code means for generating a firstcoded electronic signal in response to operation of the key means; c.timer means for disabling the lock apparatus if a first proper codedelectronic signal is not generated within a predetermined time frame; d.second code means connected to the first code means for generating asecond independently determinable coded electronic signal in responseonly to the generation of a proper first electronic coded signal; and e.electronic means responsive to said second coded electronic signal todecode said second coded signal and generate an initiating signal forinitiating the operation of a lock means.
 5. An electronic lockapparatus, comprising: a. key means including a tumbler mechanism havinga plurality of tumblers therein; b. each of said tumblers being dividedinto three or more segments for permitting said tumbler mechanism to beoperated in more than one position of said tumblers; c. first code meansfor generating a fIrst coded electronic signal in response to operationof the key means; d. said first code means including electronic switchesfor setting the first coded electronic signal; e. said electronicswitches comprising said tumblers and conductive or non-conductivesegments thereof for completing or not completing an electronic circuitdepending on the position of said tumblers; f. second code meansconnected to the first code means for generating a second independentlydeterminable coded electronic signal in response only to the generationof the first electronic coded signal; and g. electronic means responsiveto said second coded signal to decode said second coded signal andgenerate an initiating signal for initiating the operation of a lockmeans.
 6. An electronic lock apparatus, comprising: a. key meansincluding a tumbler mechanism having a plurality of tumblers therein; b.at least one of said tumblers being divided into three or more segmentsfor permitting said tumbler mechanism to be operated in more than oneposition of said tumblers; c. first code means for generating a firstcoded electronic signal in response to operation of the key means; d.said first code means including electronic switches for setting thefirst coded electronic signal; e. said electronic switches includingsaid tumblers for completing or not completing an electronic circuitdepending on the position of said tumblers; f. second code meansconnected to the first code means for generating a second independentlydeterminable coded electronic signal in response only to the generationof the first electronic coded signal; and g. electronic means responsiveto said second coded signal to decode said second signal and generate aninitiating signal for initiating the operation of a lock means.
 7. Anelectronic lock apparatus, comprising: a. key means including a tumblermechanism having a plurality of tumblers therein; b. at least one ofsaid tumblers being divided into three or more segments for permittingsaid tumbler mechanism to be operated in more than one position of saidtumblers; d. timer means for disabling the lock apparatus if a properfirst coded electronic signal is not generated within a predeterminedtime frame; e. said first code means including electronic switches forsetting the first coded electronic signal; f. said electronic switchesincluding tumblers for completing or not completing an electroniccircuit depending on the position of said tumblers; g. second code meansconnected to the first code means for generating a second independentlydeterminable coded electronic signal in response only to the generationof the first electronic coded signal; and h. electronic means responsiveto said second coded signal to decode said second signal and generate aninitiating signal for initiating the operation of a lock means.
 8. Anelectronic lock apparatus, comprising: a. key means including a tumblermechanism having a plurality of tumblers therein; b. at least one ofsaid tumblers being divided into three or more segments for permittingsaid tumber mechanism to be operated in more than one position of saidtumblers; c. first code means for generating a first coded electronicsignal in response to operation of the key means; d. timer means fordisabling the lock apparatus if the proper coded electronic signal isnot generated within a predetermined time frame; e. second code meansconnected to the first code means for generating a second independentlydeterminable coded electronic signal in response only to the generationof the first electronic coded signal; and f. electronic means responsiveto said second coded electronic signal to decode said second codedsignal and generate an initiating signal for initiating the operation ofa lock means.
 9. An electronic lock apparatus comprising: a. key meansincluding a non-rotatable key cylinder and at least one Tumbler in saidcylinder; b. said tumbler being unitary and displaceable in response tothe insertion of a key into said cylinder; c. first code means forgenerating a first coded electronic signal in response to displacementof said tumbler; d. second code means connected to the first code meansfor generating a second independently determinable coded electronicsignal in response only to the generation of a first electronic codedsignal; and e. electronic means responsive to said second coded signalto decode said second coded signal and generate an initiating signal forinitiating the operation of a lock means.
 10. An electronic lockapparatus in accordance with claim 9 wherein said first code meansincludes at least one electronic switch for setting the first codedelectronic signal, said electronic switch being responsive to thedisplacement of said tumbler by a key means.
 11. An electronic lockapparatus in accordance with claim 9 including timer means for disablingthe lock apparatus if a proper first coded electronic signal is notgenerated within a predetermined time frame.
 12. An electronic lockapparatus, comprising: a. key means including a tumbler mechanism havinga plurality of tumblers therein; b. at least one of said tumblers beingdivided into three or more segments for permitting said tumblermechanism to be operated in more than one position of said tumblers; c.first code means for generating a first coded electronic signal inresponse to operation of the key means; d. second code means connectedto the first code means for generating a second independentlydeterminable coded electronic signal in response only to the generationof the first electronic coded signal; and e. electronic means responsiveto said second coded electronic signal to decode said second codedsignal and generate an initiating signal for initiating the operation ofa lock means.